Safety elevator appliance.



A. P.VBAGBY AND I. l-THOMPSON.

SAFETY ELEVATOR APPLIANCE. APPLICATION HL'ED Fa.1,1919.

1,302,623"u I Patented May 6, 1919.

2 SHEETS-SHEET l.

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A.`P. BAGBY AND I. B. THOMPSON. SAFETY ELEvATon APPLIANCE.

@PPLICATION FILED FEB. 7, 1919. 1,302,623, Patented May 6, 1919.

2 SHEETS-SHEET 2.

ARTHUR P. BAGBY AND JOHN B. THOMPSON, 0F BIRMINGHAM, ALABAMA.

SAFETY ELEVATOR APPLIANCE.

Specification of Letters Patent.

` rammed May c, 1919.

Application filed February 7, 1919. Serial No. 275,489.

To all whom it may concern:

Be it known that we, ARTHUR P. BAGBY and Jol-1N B. THOMPSON, vcitizensof the United States of America, residing at Birmingham, in the countyof Jefferson and State of Alabama, have invented certain new and usefulImprovements in Safety lillevator Appliances, of which the following isa specification.

Our invention relates to a safety appliance for elevators and has .forits object to prevent the operation of` an elevator when a landing doorin its shaft is open.

More particularly it is our purpose to provide the elevator cab with aswitch controlling the main circuit and with a counterweighted carriageadapted to close the switch when a cam on the landing door has beenmoved to position with the door closed, otherwise this cam will hold thecarriage out of switch-closing position.

Our invention also involves the novel details of construction andarrangements' of parts, which in their preferred embodiments only areillustrated in the accompanying drawings, in which Figure 1 illustratesour invention in front elevation.

2 is a partial planview of Fig. 1.

Figs. 3 and 4. are enlarged front and end elevations of the trolley andits correlated cam and switch. w

Fig. 5 is a detail plan view enlarged of Fig. 3.

Similar reference numerals refer to similar parts throughout thedrawings.

In the embodiment of our invention illustrated, cach landing door 1 ofthe elevator shaft is provided with a cam 2 projecting above its upperend and preferably formed by a bent metal rod offset at t-op and bottomwith a vertical intermediate section long enough to make provision forthe ordinary variation in level at which the elevator may be brought torest at a landing. The elevator cab 3 may be of any construction and isprovided on its top along the front edge with a straight horizontaltrack 4 formed by a metal bar supported at its ends by angle brackets 5.On this track is mounted a carriage 6 formed of spaced plates connectedat their four corners by pins on which rollers 7 turn. rllhe rollersengage above and below the track which is interposed between the plates,thus making provision against the carriage getting olf its track. At itsend nearest the landing door the carriage is provided with a clip 8 towhich is connected a cable 9 which passes over a sheave wheel 10 andisconnected to a counter-weight 11 ljournaled therein a shaft 14 whichcarries a stop plate 15, the latter being held at right angles to thetrolley by a coil spring 16 surrounding the shaft and made fast at oneend to the trip plate and at the other end to the trolley. In its lowerportion an upwardly inclined plunger 17 is mounted having a fiber head18 and having suitable guides 19 carried by the carriage. A coil spring20 surrounds this plunger and bearing at'one end against one of thebrackets and at the other end against a seat 21 on the plunger whichforms a stop to limit its movement responsive to the spring. The fiberhead of the plunger is disposed to engage the swinging door 22 of acircuit breaker box 23, which door stands normally open with the switchopen ,circuited and which, when engaged by the plunger, is thrust intoits circuit closed position. The circuits thus controlled by this switchare illustrated in Fig. 4 and comprise a lead 24 from the operatorsswitch 25, the circuit returning by lead 26 to the safety switch 27.When the switch 28 in the breaker boX .is open the main circuitscontrolling the cab are broken and the elevator cannot be moved.

In operation, with the landing doors closed, the cams 2 are Iin positionto be cleared by the trip plate 15 as the elevator runs and ,when itcomes to rest opposite a landing and such landing door is opened,

the cam on the latter will pick up the stop plate and run the carriageback on its track, thus permitting the breaker box switch to open. Asthe landing door is closed, the counter-weight causes the carriage tofollow along on its track after the cam until the plunger closes thebreaker box switch and restores the current to the control of theoperator. lf the landing door is only partly closed, the breaker boxswitch will not be closed and the car cannot be started. lf the tripplate happens to strike any obstruction, being yieldingly pivoted to thecarriage it will give and in like manner if the landing door is closedtoo rapidly the yielding plunger will prevent injury to the breaker boxswitch. The apparatus can be inexpensively installed, and is durable andreliable in its functioning.

This invention is not intended to be restricted in scope to the speciicembodiments shown, but contemplates such modifications as come withinthe spirit and scope of the claims.

Having thus described our invention, .whatwe 'claim yas new and desire'to secure by Letters Patent, is

l. A device of ythe character described comprising `a cam mounted on 4alanding fdoor, a ,circuit breaker switch mounted :on and :adapted tocontrol electrically the stantin-g ofan elevator lcab, 1a switch closingcarriage on the cab adapted to be engaged and Amoved with said A,cam asthe door opens fto open said switch, and ,means independent of .the doorto -urgesaidcarriage to follow said .,doorfs closing movements and `toclose :sa-id kswitch wfhen the door is :fully closed.

2. A .device of the character described comprising a :cam movable with alanding door, a circuit breaker switch adapted to lcontrol the .startingofthe car and lwhich is ,mounted thereon, a switch closing carriage.adapted Ato normally -close said switch,and counter-weight means to.ur-ge fthe carriage toward its switch closing position, said'carriagebeing disposed in the path of -and ,adapted to .follow vthe movements:of ,said cam.

,3. In a safety [elevator appliance, alla-ndi-ng door `carrying a cam,,an elevator cab having aztrack .thereon ,and a circuit-breaker switch,a switch closing element [movable Valong .said ytrack by `the cam -to:open said switch, and a counterweight Y.means to .cause said .elementto .follow said :door Aas fit closes and .to 4close -said switch .onlywhen :said landing-door is fully closed.

l. In a safety elevator appliance, a landing door carrying -a cam, .anelevator cab having a-track anda carriagemovable thereon and disposedyin ,the pathfof the cam asit moves with the opening of the landingdoor, a circuit breaker switch, and .counterweight means kto normallyforce the carriage 4in (the direction .to close said switch.

5. In a safety elevator appliance, a landing door carrying a cam, anelevator cab having a-track and a carriage movable there- On, a Circuitbreaker switch, means to normally move the carriage to close saidswitch, and means on a landing door disposed to clear said carriage asthe cab moves when the door isfclosed .and to engage and shift saidcarriage as the door opens to open said switch.

l6. In combination, a landing door having a vertical double cam, anelevator having a transverse track, a carriage lmounted on the track, acircuit breaker switch, a counterweight adapted to Vmove the carriagealong said track to close said switch, said cam bc- Aing disposed tomove the carriage reversely along said track to open said switch.

7.. In combination, -a landing door having an elongated cam rodprojecting vertically above y:it .and -bent at both :ends to formrcverse cams,;a1 1e'le'vator cab .having a circuit .breaking switch,:and -a `carriage adapted to rclose said switch `v'and to clear saidvcam frod when the said door is closed :and to be engaged vand shiftedbythe ycam as the door .opens .to open said switch.

8,. An ,elevator ycab having a :circuit breaker switch `and a controllertherefor comprising a bodily shiftable carriage hav- `i-nga springplunger disposed to engage and close said switch, and means on the cabtend- .ing .to thold the vcarriage in switch closing position.

9. An elevator cab having a circuit breaker switch and a controllertherefor comprising a bodily shiftable carriage `having-1.a springplungerfdisposed to engage and :close .said switch, means on thefcabtending itc hold -the'carriage in switch closing .position, and means ona landing vdoor to dis- ;place the :carriage `from .switch closingposition when the oor opens.

ln `testimony whereof .we aiix our signatures.

ARTHUR l). 'BAGBY JOHN B. THOMPSON.

Witness NOMIE WELSH.

.Gopiesofthis patentmay be ohtainedf/or ve..cents each, by,addys5ing theCommissioner of Patents,

' Washington, J). AC.

